xref: /linux-6.15/include/linux/module.h (revision 61842868)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Dynamic loading of modules into the kernel.
4  *
5  * Rewritten by Richard Henderson <[email protected]> Dec 1996
6  * Rewritten again by Rusty Russell, 2002
7  */
8 
9 #ifndef _LINUX_MODULE_H
10 #define _LINUX_MODULE_H
11 
12 #include <linux/list.h>
13 #include <linux/stat.h>
14 #include <linux/buildid.h>
15 #include <linux/compiler.h>
16 #include <linux/cache.h>
17 #include <linux/kmod.h>
18 #include <linux/init.h>
19 #include <linux/elf.h>
20 #include <linux/stringify.h>
21 #include <linux/kobject.h>
22 #include <linux/moduleparam.h>
23 #include <linux/jump_label.h>
24 #include <linux/export.h>
25 #include <linux/rbtree_latch.h>
26 #include <linux/error-injection.h>
27 #include <linux/tracepoint-defs.h>
28 #include <linux/srcu.h>
29 #include <linux/static_call_types.h>
30 #include <linux/dynamic_debug.h>
31 
32 #include <linux/percpu.h>
33 #include <asm/module.h>
34 
35 #define MODULE_NAME_LEN MAX_PARAM_PREFIX_LEN
36 
37 struct modversion_info {
38 	unsigned long crc;
39 	char name[MODULE_NAME_LEN];
40 };
41 
42 struct module;
43 struct exception_table_entry;
44 
45 struct module_kobject {
46 	struct kobject kobj;
47 	struct module *mod;
48 	struct kobject *drivers_dir;
49 	struct module_param_attrs *mp;
50 	struct completion *kobj_completion;
51 } __randomize_layout;
52 
53 struct module_attribute {
54 	struct attribute attr;
55 	ssize_t (*show)(struct module_attribute *, struct module_kobject *,
56 			char *);
57 	ssize_t (*store)(struct module_attribute *, struct module_kobject *,
58 			 const char *, size_t count);
59 	void (*setup)(struct module *, const char *);
60 	int (*test)(struct module *);
61 	void (*free)(struct module *);
62 };
63 
64 struct module_version_attribute {
65 	struct module_attribute mattr;
66 	const char *module_name;
67 	const char *version;
68 };
69 
70 extern ssize_t __modver_version_show(struct module_attribute *,
71 				     struct module_kobject *, char *);
72 
73 extern struct module_attribute module_uevent;
74 
75 /* These are either module local, or the kernel's dummy ones. */
76 extern int init_module(void);
77 extern void cleanup_module(void);
78 
79 #ifndef MODULE
80 /**
81  * module_init() - driver initialization entry point
82  * @x: function to be run at kernel boot time or module insertion
83  *
84  * module_init() will either be called during do_initcalls() (if
85  * builtin) or at module insertion time (if a module).  There can only
86  * be one per module.
87  */
88 #define module_init(x)	__initcall(x);
89 
90 /**
91  * module_exit() - driver exit entry point
92  * @x: function to be run when driver is removed
93  *
94  * module_exit() will wrap the driver clean-up code
95  * with cleanup_module() when used with rmmod when
96  * the driver is a module.  If the driver is statically
97  * compiled into the kernel, module_exit() has no effect.
98  * There can only be one per module.
99  */
100 #define module_exit(x)	__exitcall(x);
101 
102 #else /* MODULE */
103 
104 /*
105  * In most cases loadable modules do not need custom
106  * initcall levels. There are still some valid cases where
107  * a driver may be needed early if built in, and does not
108  * matter when built as a loadable module. Like bus
109  * snooping debug drivers.
110  */
111 #define early_initcall(fn)		module_init(fn)
112 #define core_initcall(fn)		module_init(fn)
113 #define core_initcall_sync(fn)		module_init(fn)
114 #define postcore_initcall(fn)		module_init(fn)
115 #define postcore_initcall_sync(fn)	module_init(fn)
116 #define arch_initcall(fn)		module_init(fn)
117 #define subsys_initcall(fn)		module_init(fn)
118 #define subsys_initcall_sync(fn)	module_init(fn)
119 #define fs_initcall(fn)			module_init(fn)
120 #define fs_initcall_sync(fn)		module_init(fn)
121 #define rootfs_initcall(fn)		module_init(fn)
122 #define device_initcall(fn)		module_init(fn)
123 #define device_initcall_sync(fn)	module_init(fn)
124 #define late_initcall(fn)		module_init(fn)
125 #define late_initcall_sync(fn)		module_init(fn)
126 
127 #define console_initcall(fn)		module_init(fn)
128 
129 /* Each module must use one module_init(). */
130 #define module_init(initfn)					\
131 	static inline initcall_t __maybe_unused __inittest(void)		\
132 	{ return initfn; }					\
133 	int init_module(void) __copy(initfn)			\
134 		__attribute__((alias(#initfn)));		\
135 	___ADDRESSABLE(init_module, __initdata);
136 
137 /* This is only required if you want to be unloadable. */
138 #define module_exit(exitfn)					\
139 	static inline exitcall_t __maybe_unused __exittest(void)		\
140 	{ return exitfn; }					\
141 	void cleanup_module(void) __copy(exitfn)		\
142 		__attribute__((alias(#exitfn)));		\
143 	___ADDRESSABLE(cleanup_module, __exitdata);
144 
145 #endif
146 
147 /* This means "can be init if no module support, otherwise module load
148    may call it." */
149 #ifdef CONFIG_MODULES
150 #define __init_or_module
151 #define __initdata_or_module
152 #define __initconst_or_module
153 #define __INIT_OR_MODULE	.text
154 #define __INITDATA_OR_MODULE	.data
155 #define __INITRODATA_OR_MODULE	.section ".rodata","a",%progbits
156 #else
157 #define __init_or_module __init
158 #define __initdata_or_module __initdata
159 #define __initconst_or_module __initconst
160 #define __INIT_OR_MODULE __INIT
161 #define __INITDATA_OR_MODULE __INITDATA
162 #define __INITRODATA_OR_MODULE __INITRODATA
163 #endif /*CONFIG_MODULES*/
164 
165 /* Generic info of form tag = "info" */
166 #define MODULE_INFO(tag, info) __MODULE_INFO(tag, tag, info)
167 
168 /* For userspace: you can also call me... */
169 #define MODULE_ALIAS(_alias) MODULE_INFO(alias, _alias)
170 
171 /* Soft module dependencies. See man modprobe.d for details.
172  * Example: MODULE_SOFTDEP("pre: module-foo module-bar post: module-baz")
173  */
174 #define MODULE_SOFTDEP(_softdep) MODULE_INFO(softdep, _softdep)
175 
176 /*
177  * Weak module dependencies. See man modprobe.d for details.
178  * Example: MODULE_WEAKDEP("module-foo")
179  */
180 #define MODULE_WEAKDEP(_weakdep) MODULE_INFO(weakdep, _weakdep)
181 
182 /*
183  * MODULE_FILE is used for generating modules.builtin
184  * So, make it no-op when this is being built as a module
185  */
186 #ifdef MODULE
187 #define MODULE_FILE
188 #else
189 #define MODULE_FILE	MODULE_INFO(file, KBUILD_MODFILE);
190 #endif
191 
192 /*
193  * The following license idents are currently accepted as indicating free
194  * software modules
195  *
196  *	"GPL"				[GNU Public License v2]
197  *	"GPL v2"			[GNU Public License v2]
198  *	"GPL and additional rights"	[GNU Public License v2 rights and more]
199  *	"Dual BSD/GPL"			[GNU Public License v2
200  *					 or BSD license choice]
201  *	"Dual MIT/GPL"			[GNU Public License v2
202  *					 or MIT license choice]
203  *	"Dual MPL/GPL"			[GNU Public License v2
204  *					 or Mozilla license choice]
205  *
206  * The following other idents are available
207  *
208  *	"Proprietary"			[Non free products]
209  *
210  * Both "GPL v2" and "GPL" (the latter also in dual licensed strings) are
211  * merely stating that the module is licensed under the GPL v2, but are not
212  * telling whether "GPL v2 only" or "GPL v2 or later". The reason why there
213  * are two variants is a historic and failed attempt to convey more
214  * information in the MODULE_LICENSE string. For module loading the
215  * "only/or later" distinction is completely irrelevant and does neither
216  * replace the proper license identifiers in the corresponding source file
217  * nor amends them in any way. The sole purpose is to make the
218  * 'Proprietary' flagging work and to refuse to bind symbols which are
219  * exported with EXPORT_SYMBOL_GPL when a non free module is loaded.
220  *
221  * In the same way "BSD" is not a clear license information. It merely
222  * states, that the module is licensed under one of the compatible BSD
223  * license variants. The detailed and correct license information is again
224  * to be found in the corresponding source files.
225  *
226  * There are dual licensed components, but when running with Linux it is the
227  * GPL that is relevant so this is a non issue. Similarly LGPL linked with GPL
228  * is a GPL combined work.
229  *
230  * This exists for several reasons
231  * 1.	So modinfo can show license info for users wanting to vet their setup
232  *	is free
233  * 2.	So the community can ignore bug reports including proprietary modules
234  * 3.	So vendors can do likewise based on their own policies
235  */
236 #define MODULE_LICENSE(_license) MODULE_FILE MODULE_INFO(license, _license)
237 
238 /*
239  * Author(s), use "Name <email>" or just "Name", for multiple
240  * authors use multiple MODULE_AUTHOR() statements/lines.
241  */
242 #define MODULE_AUTHOR(_author) MODULE_INFO(author, _author)
243 
244 /* What your module does. */
245 #define MODULE_DESCRIPTION(_description) MODULE_INFO(description, _description)
246 
247 #ifdef MODULE
248 /* Creates an alias so file2alias.c can find device table. */
249 #define MODULE_DEVICE_TABLE(type, name)					\
250 extern typeof(name) __mod_##type##__##name##_device_table		\
251   __attribute__ ((unused, alias(__stringify(name))))
252 #else  /* !MODULE */
253 #define MODULE_DEVICE_TABLE(type, name)
254 #endif
255 
256 /* Version of form [<epoch>:]<version>[-<extra-version>].
257  * Or for CVS/RCS ID version, everything but the number is stripped.
258  * <epoch>: A (small) unsigned integer which allows you to start versions
259  * anew. If not mentioned, it's zero.  eg. "2:1.0" is after
260  * "1:2.0".
261 
262  * <version>: The <version> may contain only alphanumerics and the
263  * character `.'.  Ordered by numeric sort for numeric parts,
264  * ascii sort for ascii parts (as per RPM or DEB algorithm).
265 
266  * <extraversion>: Like <version>, but inserted for local
267  * customizations, eg "rh3" or "rusty1".
268 
269  * Using this automatically adds a checksum of the .c files and the
270  * local headers in "srcversion".
271  */
272 
273 #if defined(MODULE) || !defined(CONFIG_SYSFS)
274 #define MODULE_VERSION(_version) MODULE_INFO(version, _version)
275 #else
276 #define MODULE_VERSION(_version)					\
277 	MODULE_INFO(version, _version);					\
278 	static struct module_version_attribute __modver_attr		\
279 		__used __section("__modver")				\
280 		__aligned(__alignof__(struct module_version_attribute)) \
281 		= {							\
282 			.mattr	= {					\
283 				.attr	= {				\
284 					.name	= "version",		\
285 					.mode	= S_IRUGO,		\
286 				},					\
287 				.show	= __modver_version_show,	\
288 			},						\
289 			.module_name	= KBUILD_MODNAME,		\
290 			.version	= _version,			\
291 		}
292 #endif
293 
294 /* Optional firmware file (or files) needed by the module
295  * format is simply firmware file name.  Multiple firmware
296  * files require multiple MODULE_FIRMWARE() specifiers */
297 #define MODULE_FIRMWARE(_firmware) MODULE_INFO(firmware, _firmware)
298 
299 #define MODULE_IMPORT_NS(ns)	MODULE_INFO(import_ns, __stringify(ns))
300 
301 struct notifier_block;
302 
303 #ifdef CONFIG_MODULES
304 
305 extern int modules_disabled; /* for sysctl */
306 /* Get/put a kernel symbol (calls must be symmetric) */
307 void *__symbol_get(const char *symbol);
308 void *__symbol_get_gpl(const char *symbol);
309 #define symbol_get(x) ((typeof(&x))(__symbol_get(__stringify(x))))
310 
311 /* modules using other modules: kdb wants to see this. */
312 struct module_use {
313 	struct list_head source_list;
314 	struct list_head target_list;
315 	struct module *source, *target;
316 };
317 
318 enum module_state {
319 	MODULE_STATE_LIVE,	/* Normal state. */
320 	MODULE_STATE_COMING,	/* Full formed, running module_init. */
321 	MODULE_STATE_GOING,	/* Going away. */
322 	MODULE_STATE_UNFORMED,	/* Still setting it up. */
323 };
324 
325 struct mod_tree_node {
326 	struct module *mod;
327 	struct latch_tree_node node;
328 };
329 
330 enum mod_mem_type {
331 	MOD_TEXT = 0,
332 	MOD_DATA,
333 	MOD_RODATA,
334 	MOD_RO_AFTER_INIT,
335 	MOD_INIT_TEXT,
336 	MOD_INIT_DATA,
337 	MOD_INIT_RODATA,
338 
339 	MOD_MEM_NUM_TYPES,
340 	MOD_INVALID = -1,
341 };
342 
343 #define mod_mem_type_is_init(type)	\
344 	((type) == MOD_INIT_TEXT ||	\
345 	 (type) == MOD_INIT_DATA ||	\
346 	 (type) == MOD_INIT_RODATA)
347 
348 #define mod_mem_type_is_core(type) (!mod_mem_type_is_init(type))
349 
350 #define mod_mem_type_is_text(type)	\
351 	 ((type) == MOD_TEXT ||		\
352 	  (type) == MOD_INIT_TEXT)
353 
354 #define mod_mem_type_is_data(type) (!mod_mem_type_is_text(type))
355 
356 #define mod_mem_type_is_core_data(type)	\
357 	(mod_mem_type_is_core(type) &&	\
358 	 mod_mem_type_is_data(type))
359 
360 #define for_each_mod_mem_type(type)			\
361 	for (enum mod_mem_type (type) = 0;		\
362 	     (type) < MOD_MEM_NUM_TYPES; (type)++)
363 
364 #define for_class_mod_mem_type(type, class)		\
365 	for_each_mod_mem_type(type)			\
366 		if (mod_mem_type_is_##class(type))
367 
368 struct module_memory {
369 	void *base;
370 	unsigned int size;
371 
372 #ifdef CONFIG_MODULES_TREE_LOOKUP
373 	struct mod_tree_node mtn;
374 #endif
375 };
376 
377 #ifdef CONFIG_MODULES_TREE_LOOKUP
378 /* Only touch one cacheline for common rbtree-for-core-layout case. */
379 #define __module_memory_align ____cacheline_aligned
380 #else
381 #define __module_memory_align
382 #endif
383 
384 struct mod_kallsyms {
385 	Elf_Sym *symtab;
386 	unsigned int num_symtab;
387 	char *strtab;
388 	char *typetab;
389 };
390 
391 #ifdef CONFIG_LIVEPATCH
392 /**
393  * struct klp_modinfo - ELF information preserved from the livepatch module
394  *
395  * @hdr: ELF header
396  * @sechdrs: Section header table
397  * @secstrings: String table for the section headers
398  * @symndx: The symbol table section index
399  */
400 struct klp_modinfo {
401 	Elf_Ehdr hdr;
402 	Elf_Shdr *sechdrs;
403 	char *secstrings;
404 	unsigned int symndx;
405 };
406 #endif
407 
408 struct module {
409 	enum module_state state;
410 
411 	/* Member of list of modules */
412 	struct list_head list;
413 
414 	/* Unique handle for this module */
415 	char name[MODULE_NAME_LEN];
416 
417 #ifdef CONFIG_STACKTRACE_BUILD_ID
418 	/* Module build ID */
419 	unsigned char build_id[BUILD_ID_SIZE_MAX];
420 #endif
421 
422 	/* Sysfs stuff. */
423 	struct module_kobject mkobj;
424 	struct module_attribute *modinfo_attrs;
425 	const char *version;
426 	const char *srcversion;
427 	struct kobject *holders_dir;
428 
429 	/* Exported symbols */
430 	const struct kernel_symbol *syms;
431 	const s32 *crcs;
432 	unsigned int num_syms;
433 
434 #ifdef CONFIG_ARCH_USES_CFI_TRAPS
435 	s32 *kcfi_traps;
436 	s32 *kcfi_traps_end;
437 #endif
438 
439 	/* Kernel parameters. */
440 #ifdef CONFIG_SYSFS
441 	struct mutex param_lock;
442 #endif
443 	struct kernel_param *kp;
444 	unsigned int num_kp;
445 
446 	/* GPL-only exported symbols. */
447 	unsigned int num_gpl_syms;
448 	const struct kernel_symbol *gpl_syms;
449 	const s32 *gpl_crcs;
450 	bool using_gplonly_symbols;
451 
452 #ifdef CONFIG_MODULE_SIG
453 	/* Signature was verified. */
454 	bool sig_ok;
455 #endif
456 
457 	bool async_probe_requested;
458 
459 	/* Exception table */
460 	unsigned int num_exentries;
461 	struct exception_table_entry *extable;
462 
463 	/* Startup function. */
464 	int (*init)(void);
465 
466 	struct module_memory mem[MOD_MEM_NUM_TYPES] __module_memory_align;
467 
468 	/* Arch-specific module values */
469 	struct mod_arch_specific arch;
470 
471 	unsigned long taints;	/* same bits as kernel:taint_flags */
472 
473 #ifdef CONFIG_GENERIC_BUG
474 	/* Support for BUG */
475 	unsigned num_bugs;
476 	struct list_head bug_list;
477 	struct bug_entry *bug_table;
478 #endif
479 
480 #ifdef CONFIG_KALLSYMS
481 	/* Protected by RCU and/or module_mutex: use rcu_dereference() */
482 	struct mod_kallsyms __rcu *kallsyms;
483 	struct mod_kallsyms core_kallsyms;
484 
485 	/* Section attributes */
486 	struct module_sect_attrs *sect_attrs;
487 
488 	/* Notes attributes */
489 	struct module_notes_attrs *notes_attrs;
490 #endif
491 
492 	/* The command line arguments (may be mangled).  People like
493 	   keeping pointers to this stuff */
494 	char *args;
495 
496 #ifdef CONFIG_SMP
497 	/* Per-cpu data. */
498 	void __percpu *percpu;
499 	unsigned int percpu_size;
500 #endif
501 	void *noinstr_text_start;
502 	unsigned int noinstr_text_size;
503 
504 #ifdef CONFIG_TRACEPOINTS
505 	unsigned int num_tracepoints;
506 	tracepoint_ptr_t *tracepoints_ptrs;
507 #endif
508 #ifdef CONFIG_TREE_SRCU
509 	unsigned int num_srcu_structs;
510 	struct srcu_struct **srcu_struct_ptrs;
511 #endif
512 #ifdef CONFIG_BPF_EVENTS
513 	unsigned int num_bpf_raw_events;
514 	struct bpf_raw_event_map *bpf_raw_events;
515 #endif
516 #ifdef CONFIG_DEBUG_INFO_BTF_MODULES
517 	unsigned int btf_data_size;
518 	void *btf_data;
519 #endif
520 #ifdef CONFIG_JUMP_LABEL
521 	struct jump_entry *jump_entries;
522 	unsigned int num_jump_entries;
523 #endif
524 #ifdef CONFIG_TRACING
525 	unsigned int num_trace_bprintk_fmt;
526 	const char **trace_bprintk_fmt_start;
527 #endif
528 #ifdef CONFIG_EVENT_TRACING
529 	struct trace_event_call **trace_events;
530 	unsigned int num_trace_events;
531 	struct trace_eval_map **trace_evals;
532 	unsigned int num_trace_evals;
533 #endif
534 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
535 	unsigned int num_ftrace_callsites;
536 	unsigned long *ftrace_callsites;
537 #endif
538 #ifdef CONFIG_KPROBES
539 	void *kprobes_text_start;
540 	unsigned int kprobes_text_size;
541 	unsigned long *kprobe_blacklist;
542 	unsigned int num_kprobe_blacklist;
543 #endif
544 #ifdef CONFIG_HAVE_STATIC_CALL_INLINE
545 	int num_static_call_sites;
546 	struct static_call_site *static_call_sites;
547 #endif
548 #if IS_ENABLED(CONFIG_KUNIT)
549 	int num_kunit_init_suites;
550 	struct kunit_suite **kunit_init_suites;
551 	int num_kunit_suites;
552 	struct kunit_suite **kunit_suites;
553 #endif
554 
555 
556 #ifdef CONFIG_LIVEPATCH
557 	bool klp; /* Is this a livepatch module? */
558 	bool klp_alive;
559 
560 	/* ELF information */
561 	struct klp_modinfo *klp_info;
562 #endif
563 
564 #ifdef CONFIG_PRINTK_INDEX
565 	unsigned int printk_index_size;
566 	struct pi_entry **printk_index_start;
567 #endif
568 
569 #ifdef CONFIG_MODULE_UNLOAD
570 	/* What modules depend on me? */
571 	struct list_head source_list;
572 	/* What modules do I depend on? */
573 	struct list_head target_list;
574 
575 	/* Destruction function. */
576 	void (*exit)(void);
577 
578 	atomic_t refcnt;
579 #endif
580 
581 #ifdef CONFIG_CONSTRUCTORS
582 	/* Constructor functions. */
583 	ctor_fn_t *ctors;
584 	unsigned int num_ctors;
585 #endif
586 
587 #ifdef CONFIG_FUNCTION_ERROR_INJECTION
588 	struct error_injection_entry *ei_funcs;
589 	unsigned int num_ei_funcs;
590 #endif
591 #ifdef CONFIG_DYNAMIC_DEBUG_CORE
592 	struct _ddebug_info dyndbg_info;
593 #endif
594 } ____cacheline_aligned __randomize_layout;
595 #ifndef MODULE_ARCH_INIT
596 #define MODULE_ARCH_INIT {}
597 #endif
598 
599 #ifndef HAVE_ARCH_KALLSYMS_SYMBOL_VALUE
600 static inline unsigned long kallsyms_symbol_value(const Elf_Sym *sym)
601 {
602 	return sym->st_value;
603 }
604 #endif
605 
606 /* FIXME: It'd be nice to isolate modules during init, too, so they
607    aren't used before they (may) fail.  But presently too much code
608    (IDE & SCSI) require entry into the module during init.*/
609 static inline bool module_is_live(struct module *mod)
610 {
611 	return mod->state != MODULE_STATE_GOING;
612 }
613 
614 static inline bool module_is_coming(struct module *mod)
615 {
616         return mod->state == MODULE_STATE_COMING;
617 }
618 
619 struct module *__module_text_address(unsigned long addr);
620 struct module *__module_address(unsigned long addr);
621 bool is_module_address(unsigned long addr);
622 bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr);
623 bool is_module_percpu_address(unsigned long addr);
624 bool is_module_text_address(unsigned long addr);
625 
626 static inline bool within_module_mem_type(unsigned long addr,
627 					  const struct module *mod,
628 					  enum mod_mem_type type)
629 {
630 	unsigned long base, size;
631 
632 	base = (unsigned long)mod->mem[type].base;
633 	size = mod->mem[type].size;
634 	return addr - base < size;
635 }
636 
637 static inline bool within_module_core(unsigned long addr,
638 				      const struct module *mod)
639 {
640 	for_class_mod_mem_type(type, core) {
641 		if (within_module_mem_type(addr, mod, type))
642 			return true;
643 	}
644 	return false;
645 }
646 
647 static inline bool within_module_init(unsigned long addr,
648 				      const struct module *mod)
649 {
650 	for_class_mod_mem_type(type, init) {
651 		if (within_module_mem_type(addr, mod, type))
652 			return true;
653 	}
654 	return false;
655 }
656 
657 static inline bool within_module(unsigned long addr, const struct module *mod)
658 {
659 	return within_module_init(addr, mod) || within_module_core(addr, mod);
660 }
661 
662 /* Search for module by name: must be in a RCU-sched critical section. */
663 struct module *find_module(const char *name);
664 
665 extern void __noreturn __module_put_and_kthread_exit(struct module *mod,
666 			long code);
667 #define module_put_and_kthread_exit(code) __module_put_and_kthread_exit(THIS_MODULE, code)
668 
669 #ifdef CONFIG_MODULE_UNLOAD
670 int module_refcount(struct module *mod);
671 void __symbol_put(const char *symbol);
672 #define symbol_put(x) __symbol_put(__stringify(x))
673 void symbol_put_addr(void *addr);
674 
675 /* Sometimes we know we already have a refcount, and it's easier not
676    to handle the error case (which only happens with rmmod --wait). */
677 extern void __module_get(struct module *module);
678 
679 /**
680  * try_module_get() - take module refcount unless module is being removed
681  * @module: the module we should check for
682  *
683  * Only try to get a module reference count if the module is not being removed.
684  * This call will fail if the module is in the process of being removed.
685  *
686  * Care must also be taken to ensure the module exists and is alive prior to
687  * usage of this call. This can be gauranteed through two means:
688  *
689  * 1) Direct protection: you know an earlier caller must have increased the
690  *    module reference through __module_get(). This can typically be achieved
691  *    by having another entity other than the module itself increment the
692  *    module reference count.
693  *
694  * 2) Implied protection: there is an implied protection against module
695  *    removal. An example of this is the implied protection used by kernfs /
696  *    sysfs. The sysfs store / read file operations are guaranteed to exist
697  *    through the use of kernfs's active reference (see kernfs_active()) and a
698  *    sysfs / kernfs file removal cannot happen unless the same file is not
699  *    active. Therefore, if a sysfs file is being read or written to the module
700  *    which created it must still exist. It is therefore safe to use
701  *    try_module_get() on module sysfs store / read ops.
702  *
703  * One of the real values to try_module_get() is the module_is_live() check
704  * which ensures that the caller of try_module_get() can yield to userspace
705  * module removal requests and gracefully fail if the module is on its way out.
706  *
707  * Returns true if the reference count was successfully incremented.
708  */
709 extern bool try_module_get(struct module *module);
710 
711 /**
712  * module_put() - release a reference count to a module
713  * @module: the module we should release a reference count for
714  *
715  * If you successfully bump a reference count to a module with try_module_get(),
716  * when you are finished you must call module_put() to release that reference
717  * count.
718  */
719 extern void module_put(struct module *module);
720 
721 #else /*!CONFIG_MODULE_UNLOAD*/
722 static inline bool try_module_get(struct module *module)
723 {
724 	return !module || module_is_live(module);
725 }
726 static inline void module_put(struct module *module)
727 {
728 }
729 static inline void __module_get(struct module *module)
730 {
731 }
732 #define symbol_put(x) do { } while (0)
733 #define symbol_put_addr(p) do { } while (0)
734 
735 #endif /* CONFIG_MODULE_UNLOAD */
736 
737 /* This is a #define so the string doesn't get put in every .o file */
738 #define module_name(mod)			\
739 ({						\
740 	struct module *__mod = (mod);		\
741 	__mod ? __mod->name : "kernel";		\
742 })
743 
744 /* Dereference module function descriptor */
745 void *dereference_module_function_descriptor(struct module *mod, void *ptr);
746 
747 int register_module_notifier(struct notifier_block *nb);
748 int unregister_module_notifier(struct notifier_block *nb);
749 
750 extern void print_modules(void);
751 
752 static inline bool module_requested_async_probing(struct module *module)
753 {
754 	return module && module->async_probe_requested;
755 }
756 
757 static inline bool is_livepatch_module(struct module *mod)
758 {
759 #ifdef CONFIG_LIVEPATCH
760 	return mod->klp;
761 #else
762 	return false;
763 #endif
764 }
765 
766 void set_module_sig_enforced(void);
767 
768 #else /* !CONFIG_MODULES... */
769 
770 static inline struct module *__module_address(unsigned long addr)
771 {
772 	return NULL;
773 }
774 
775 static inline struct module *__module_text_address(unsigned long addr)
776 {
777 	return NULL;
778 }
779 
780 static inline bool is_module_address(unsigned long addr)
781 {
782 	return false;
783 }
784 
785 static inline bool is_module_percpu_address(unsigned long addr)
786 {
787 	return false;
788 }
789 
790 static inline bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
791 {
792 	return false;
793 }
794 
795 static inline bool is_module_text_address(unsigned long addr)
796 {
797 	return false;
798 }
799 
800 static inline bool within_module_core(unsigned long addr,
801 				      const struct module *mod)
802 {
803 	return false;
804 }
805 
806 static inline bool within_module_init(unsigned long addr,
807 				      const struct module *mod)
808 {
809 	return false;
810 }
811 
812 static inline bool within_module(unsigned long addr, const struct module *mod)
813 {
814 	return false;
815 }
816 
817 /* Get/put a kernel symbol (calls should be symmetric) */
818 #define symbol_get(x) ({ extern typeof(x) x __attribute__((weak,visibility("hidden"))); &(x); })
819 #define symbol_put(x) do { } while (0)
820 #define symbol_put_addr(x) do { } while (0)
821 
822 static inline void __module_get(struct module *module)
823 {
824 }
825 
826 static inline bool try_module_get(struct module *module)
827 {
828 	return true;
829 }
830 
831 static inline void module_put(struct module *module)
832 {
833 }
834 
835 #define module_name(mod) "kernel"
836 
837 static inline int register_module_notifier(struct notifier_block *nb)
838 {
839 	/* no events will happen anyway, so this can always succeed */
840 	return 0;
841 }
842 
843 static inline int unregister_module_notifier(struct notifier_block *nb)
844 {
845 	return 0;
846 }
847 
848 #define module_put_and_kthread_exit(code) kthread_exit(code)
849 
850 static inline void print_modules(void)
851 {
852 }
853 
854 static inline bool module_requested_async_probing(struct module *module)
855 {
856 	return false;
857 }
858 
859 
860 static inline void set_module_sig_enforced(void)
861 {
862 }
863 
864 /* Dereference module function descriptor */
865 static inline
866 void *dereference_module_function_descriptor(struct module *mod, void *ptr)
867 {
868 	return ptr;
869 }
870 
871 static inline bool module_is_coming(struct module *mod)
872 {
873 	return false;
874 }
875 #endif /* CONFIG_MODULES */
876 
877 #ifdef CONFIG_SYSFS
878 extern struct kset *module_kset;
879 extern const struct kobj_type module_ktype;
880 #endif /* CONFIG_SYSFS */
881 
882 #define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x)
883 
884 /* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */
885 
886 #define __MODULE_STRING(x) __stringify(x)
887 
888 #ifdef CONFIG_GENERIC_BUG
889 void module_bug_finalize(const Elf_Ehdr *, const Elf_Shdr *,
890 			 struct module *);
891 void module_bug_cleanup(struct module *);
892 
893 #else	/* !CONFIG_GENERIC_BUG */
894 
895 static inline void module_bug_finalize(const Elf_Ehdr *hdr,
896 					const Elf_Shdr *sechdrs,
897 					struct module *mod)
898 {
899 }
900 static inline void module_bug_cleanup(struct module *mod) {}
901 #endif	/* CONFIG_GENERIC_BUG */
902 
903 #ifdef CONFIG_MITIGATION_RETPOLINE
904 extern bool retpoline_module_ok(bool has_retpoline);
905 #else
906 static inline bool retpoline_module_ok(bool has_retpoline)
907 {
908 	return true;
909 }
910 #endif
911 
912 #ifdef CONFIG_MODULE_SIG
913 bool is_module_sig_enforced(void);
914 
915 static inline bool module_sig_ok(struct module *module)
916 {
917 	return module->sig_ok;
918 }
919 #else	/* !CONFIG_MODULE_SIG */
920 static inline bool is_module_sig_enforced(void)
921 {
922 	return false;
923 }
924 
925 static inline bool module_sig_ok(struct module *module)
926 {
927 	return true;
928 }
929 #endif	/* CONFIG_MODULE_SIG */
930 
931 #if defined(CONFIG_MODULES) && defined(CONFIG_KALLSYMS)
932 int module_kallsyms_on_each_symbol(const char *modname,
933 				   int (*fn)(void *, const char *, unsigned long),
934 				   void *data);
935 
936 /* For kallsyms to ask for address resolution.  namebuf should be at
937  * least KSYM_NAME_LEN long: a pointer to namebuf is returned if
938  * found, otherwise NULL.
939  */
940 const char *module_address_lookup(unsigned long addr,
941 				  unsigned long *symbolsize,
942 				  unsigned long *offset,
943 				  char **modname, const unsigned char **modbuildid,
944 				  char *namebuf);
945 int lookup_module_symbol_name(unsigned long addr, char *symname);
946 int lookup_module_symbol_attrs(unsigned long addr,
947 			       unsigned long *size,
948 			       unsigned long *offset,
949 			       char *modname,
950 			       char *name);
951 
952 /* Returns 0 and fills in value, defined and namebuf, or -ERANGE if
953  * symnum out of range.
954  */
955 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
956 		       char *name, char *module_name, int *exported);
957 
958 /* Look for this name: can be of form module:name. */
959 unsigned long module_kallsyms_lookup_name(const char *name);
960 
961 unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name);
962 
963 #else	/* CONFIG_MODULES && CONFIG_KALLSYMS */
964 
965 static inline int module_kallsyms_on_each_symbol(const char *modname,
966 						 int (*fn)(void *, const char *, unsigned long),
967 						 void *data)
968 {
969 	return -EOPNOTSUPP;
970 }
971 
972 /* For kallsyms to ask for address resolution.  NULL means not found. */
973 static inline const char *module_address_lookup(unsigned long addr,
974 						unsigned long *symbolsize,
975 						unsigned long *offset,
976 						char **modname,
977 						const unsigned char **modbuildid,
978 						char *namebuf)
979 {
980 	return NULL;
981 }
982 
983 static inline int lookup_module_symbol_name(unsigned long addr, char *symname)
984 {
985 	return -ERANGE;
986 }
987 
988 static inline int module_get_kallsym(unsigned int symnum, unsigned long *value,
989 				     char *type, char *name,
990 				     char *module_name, int *exported)
991 {
992 	return -ERANGE;
993 }
994 
995 static inline unsigned long module_kallsyms_lookup_name(const char *name)
996 {
997 	return 0;
998 }
999 
1000 static inline unsigned long find_kallsyms_symbol_value(struct module *mod,
1001 						       const char *name)
1002 {
1003 	return 0;
1004 }
1005 
1006 #endif  /* CONFIG_MODULES && CONFIG_KALLSYMS */
1007 
1008 #endif /* _LINUX_MODULE_H */
1009